The rapid development of air filters is closely related to the development of the military industry and the electronics industry. Glass fiber filter media for air filtration was patented in the United States in October 1940. In the 1950s, the United States conducted in-depth research on the production process of glass fiber filter paper, which improved and developed the air filter. In the 1960s, HEPA filters were introduced. In the 1970s, HEPA filters using fine glass fiber filter paper as a filter medium had a filtration efficiency of 99.9998% for 013 micron particles. Since the 1980s, with the advent of new test methods, improved evaluation of use, and increased requirements for filtration performance, HEPA filters have been found to have serious problems, resulting in higher performance ULPA filters. At present, countries are still working hard to study, and it is estimated that more advanced air filters will appear soon.
The most important of these is the removal of the separator, ie the development of a separatorless filter. The non-separator filter not only eliminates the risk of the partition plate damaging the filter media, but also effectively increases the filter area, improves filtration efficiency, and reduces airflow resistance, thereby reducing energy consumption. In addition, the air filter has made great progress in high temperature resistance, corrosion resistance, waterproofing and antibacterial, and has met some special needs.